Kinetic Energy: Consider a baseball flying through the air. The ball is said to have "kinetic energy" by virtue of the fact that its in motion relative to the ground. You can see that it is has energy because it can do "work" on an object on the ground if it collides with it (either by pushing on it and/or damaging it during the collision). The formula for Kinetic energy, and for some of the other forms of energy described in this section will, is given in a later section of this primer.

Potential Energy: Consider a book sitting on a table. The book is said to have "potential energy" because if it is nudged off, gravity will accelerate the book, giving the book kinetic energy. Because the Earth's gravity is necessary to create this kinetic energy, and because this gravity depends on the Earth being present, we say that the "Earth-book system" is what really possesses this potential energy, and that this energy is converted into kinetic energy as the book falls.

Thermal, or heat energy:Consider a hot cup of coffee. The coffee is said to possess "thermal energy", or "heat energy" which is really the collective, microscopic, kinetic and potential energy of the molecules in the coffee (the molecules have kinetic energy because they are moving and vibrating, and they have potential energy due their mutual attraction for one another - much the same way that the book and the Earth have potential energy because they attract each other). Temperature is really a measure of how much thermal energy something has. The higher the temperature, the faster the molecules are moving around and/or vibrating, i.e. the more kinetic and potential energy the molecules have.

Chemical Energy:Consider the ability of your body to do work. The glucose (blood sugar) in your body is said to have "chemical energy" because the glucose releases energy when chemically reacted (combusted) with oxygen. Your muscles use this energy to generate mechanical force and also heat. Chemical energy is really a form of microscopic potential energy, which exists because of the electric and magnetic forces of attraction exerted between the different parts of each molecule - the same attractive forces involved in thermal vibrations. These parts get rearranged in chemical reactions, releasing or adding to this potential energy.

Electrical EnergyAll matter is made up of atoms, and atoms are made up of smaller particles, called protons (which have positive charge), neutrons (which have neutral charge), and electrons (which are negatively charged). Electrons orbit around the center, or nucleus, of atoms, just like the moon orbits the earth. The nucleus is made up of neutrons and protons. Some material, particularly metals, have certain electrons that are only loosely attached to their atoms. They can easily be made to move from one atom to another if an electric field is applied to them. When those electrons move among the atoms of matter, a current of electricity is created. This is what happens in a piece of wire when an electric field, or voltage, is applied. The electrons pass from atom to atom, pushed by the electric field and by each other (they repel each other because like charges repel), thus creating the electrical current. The measure of how well something conducts electricity is called its conductivity, and the reciprocal of conductivity is called the resistance. Copper is used for many wires because it has a lower resistance than many other metals and is easy to use and obtain. Most of the wires in your house are made of copper. Some older homes still use aluminum wiring. The energy is really transferred by the chain of repulsive interactions between the electrons down the wire - not by the transfer of electrons per se. This is just like the way that water molecules can push on each other and transmit pressure (or force) through a pipe carrying water. At points where a strong resistance is encountered, its harder for the electrons to...

...“The energy for life comes from the sun.”
Outline the role of the photosynthesis process to explain what is meant by this statement. (3 marks) chlorophyll
6CO2(g) + 6H2O(l) + energy C6 H12 O6 (aq) + 6O2(g)
2830 kJ glucose
Photosynthesis is the process in which plants use the sun’s light energy to convert carbon dioxide and water into carbohydrates such as glucose, sucrose, starch and...

...EXPERIMENT : - 2
EXPERIMENT Verification of Bernoulli’s Energy Equation
THEORY
For steady incompressible flow Bernoulli’s energy equation along a streamline is written as
[pic] constant
where
[pic] = pressure, [pic] = velocity and [pic] = height from datum
Purpose of this experiment is to verify this expression. In the special apparatus the pipe is tapered with the cross section decreasing in the...

...Part B
Now, suppose that Zak's younger cousin, Greta, sees him sliding and takes off her shoes so that she can slide as well (assume her socks have the same coefficient of kinetic friction as Zak's). Instead of getting a running start, she asks Zak to give her a push. So, Zak pushes her with a force of 125 \rm N over a distance of 1.00 \rm m. If her mass is 20.0 \rm kg, what distance d_2 does she slide after Zak's push ends?
Remember that the frictional force acts on Greta...

...uniform disk of radius R = 0.25 m has a string wrapped around it, and a m = 3 kg weight is hanging on the string. The system of the weight and disk is released from rest.
a) When the 3 kg weight is moving with a speed of 2.2 m/s, what is the kineticenergy of the entire system?
KETOT = KEwheel+KEweight
= (1/2)(I)(w2)+(1/2)(m*v2)
=(0.5* v2)(m+1/2M)
=0.5*(2.2^2)*(3+(.5*15)) J
b) If the system started from...

... Kinetic theory (or the kinetic or kinetic-molecular theory of gases) is the theory that HYPERLINK http//en.wikipedia.org/wiki/Gasgases are made up of a large number of small particles (HYPERLINK http//en.wikipedia.org/wiki/Atomatoms or HYPERLINK http//en.wikipedia.org/wiki/Moleculemolecules), all of which are in constant, HYPERLINK http//en.wikipedia.org/wiki/Randomnessrandom HYPERLINK http//en.wikipedia.org/wiki/Motion_(physics)motion. The rapidly...

...shown above. The potential energy of the ball is zero at the bottom of the cliff. Use g = 10 meters per second squared.
a. Calculate the potential, kinetic, and focal energies of the ball at time t = O.
b. On the axes below, sketch and Label graphs of the potential, kinetic, and total energies of the ball as functions of the distance fallen from the top of the cliff
cliff
cliff
c. On the axes below...